Telegraphic sending-circuit.



Y E. S. PRIDHAM. TELEGRAPHIC summa' cmcuw. APPLICATION ylCiLED AUG.22.HHG; y Patented Aug. 20, 1918 '2 SHEETSHSHEET l.

Figi.

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INVENTQR E.s.P|mJHA'1\/|.l TELEGRAPHIC summe CIRCUIT. I APPLICATIONFILED AUG.22` i916` 1,276,412. v PatentedAug.20,1918.

2 SHEETS-SHEET 2.

EDWIN s. remnant; or san rmciscdgcamroma, assmnon 'ro 4commineral.

', Winn-Ess c nnvnnornmrr cajon aan rnancrsco, CALIFORNIA, a

' 'Horror Almozara. f y y 'TELE 1,276,412.-

,4 Tb allwhom it mog] concern: A

y Be it' knownthnt 1;Enwm S. Pnmm'n, a citizen of theUnitegStatesfreBidiDgat the city and county 4o San Francisco and Stateof California, have invented new and 44ing-Circuits, 'of which the ospecification.' S j f H y y Y lIn large radio stations whereconsiderable amounts 'bf energy. arev handled in the key circuitsfforsignaling, a great amount of trouble has been experiencedwith-'thereutafvcts'tof 4controlling keys onvaccount `of the llo'wing isa `ThisA has been of especial'troublefin those ,thosestaltionsusing'undamped wayesgen-4 erated from a .direct current sources vAs 20with all forms of electric circuitsf-theymost trouble is experienced inopening the circuit,`

that is, in dra-wing two closed contacts apart. A ne ligibleamountofsparking takes place on c osing' the clrcuitf,

Theme in object of the present invention is top revent the sparkingat-the reciprocatingcontacts on the breakinglofgthe circuit.4 The methodof doingY this is toshunt the closure i n. f the circuit, immediatelybefore the fopen-r ing of-thecontactnloa brush `and rotatin commutatorarrangement so thatwhfen the brush s lvvil'isoifV the conductingsegment'of the commutetor'the arcingtakes Aplace there.

f Since :the area of contact `between ,the

'brush nd ment aaiid l the length of the insulatin a may be made 'as`largeas desired it wllllbe apparent ,that .the arcing' will do far lesereciproca-tin contacts.

v'It should' 'noted that the function of the rotating commutator isonlyto break the current jwhenrthecircuit is shuntedto it and it has nofunction in determinin'ga dash or 'The is nosynchronism between thesendin "key,and.the)rotatingcommutator and it 4' y necessary that thespeed-of rotation d ich' that when the sending key is raised 50j abreakwi'll.bef-made'-j on the cox'nmutator 'a'beforethe ke can beagaindepressed.V The #here ly ythis Iresultv is successully ac- :pechlcatipnVo! Letters latent. .Annoncen mea aannemen. semi' ne. nasse.

useful Improvements in `Telefgraphic Send,

intense arein'guwhen the contacts are opened.

sy'stems where the ener y ofthe antenna/circuit is dlrecty change orinterrupted as 1n,l

the c ommutator conducting VVsegdamage under this.l arrangement thanwith;-

CORPORA- cnarnrc smmmc-emcurr.

Patented Aug". 2o, i918.

com plishedl are shown inthe accompanying'y drawings and explained inIthe following de- Scrl tion: I

L lgure 1 shows a dia ammatic view of a 4.preferred form of the eviceembodying my Fig. 2 shows a diagram of 1 rangement of `the Same.

In the preferred form of the device a main circuit 10, in which isincluded' the source of energy to be varied such as a shunted portion of the transmitting helix of an are generator "circuit, has the spacedterminals 11." These means of a contact `piece 12 mounted-on the4armature 13 of the relay 14: The relay 14 is connected in the isincluded the batteryl4 and `the key [16.

In parallel with the main circuit is an be termedwthe Amain auxiliarycircuitz 'n-' eluded in which is a pair-.of spaced terminals 19 and therotating switch Af 'A contact piece 20mi the armature 21 of a secondrelamagnet 22is adaptedto close the terminali; 19; VThe relay magnet 22 hasa energizing circuit 23 includingthe battery 17 and Vin which `is a' airof spaced terminals 24 adept-i ed.to be c osed by thecdntact piece25-onv the armature 13.- i `he rotating switch 4'A .comprises therotatable shaft 26, carrying a conducting 'ring:` 27 with which astationary brush 28 contacts,` Aand a conducting segment '29,electricallyconnected to the ring' 27 and adapted to be su ating'segment31 `coperating with the conducting segment. l

Consider the operation ofthe .device 'for cuits are open andthecommutator is running atiamarbitrary s eed of 30 revolutions per second.The han key 161isdepresse'd,y

a modified arlocal 'circuit 15in which terminals 11 can be opened andclosed by.

2 auxiliary circuit 18 which will 'hereinafter I fis 'en aged byastationary brush 430 and an in.

closure of the main circuit 10...` All the cirsus th relay 14 energizedwhich 4brings down thearmature 1 3 andthe terminals 1v1" are closed bythecontactlfpiece v1,2. Y

s soon,as armature'. 13 comes down ter-- minals 24 are closed by contactpiece 25 'and thusthe relayl 22 is energized by .current from battery.17 thereby closing terminals@V 19 by contact piece `20. Theterminala119forma part of the main auxiliaryclicuit.18. l

Immun ductn 'xement 41 of tho' rotating-'switch C.

10 tent/.ly

25 vliliitlithe mail). auxiliaryl circuitjwhen Y cndllct-ig PWS.

.is soon as n conducting segment 29V4 comes under the brush 30 the mam.auxiliary oir-- fluitf, is completedI and is in parallel with the" :naincirctntv10.,y I

Since the cmnrnutator is running at it high freed 'it will be. seen thetwo circuits respecti vol y to terminals 11 and 19 ure olosedpracticallysimulta-heouslyi T hun the main'oin cuit 10 is closed directly atll .andintermit- 1 through the commutato'r at 19, Howlf'r, i't will beunderstood that long as the lte'iflnihals 11 are directlyhort Circuit/edby -co'ntc'zt' piece 12, th 4intermittentfatiion of the commutator willhuye no 'effeotron the um.. l he hand key 16 control's'the duration ofthe short iuitf tet-nitida 11,8?J itffor a dot or a' di' "om r a ver ortintorval ottime the hand. y is raised,

traniiferred to the. conducting' augment 29 lnxu'brush 30 of the mainauxiliary .circuit 18, thl circuit at 11 is openod Without spark andthen the rotation of the. oommutatlor t e under .the

Forl the .successful o ration of the `ftrnns mitting ldevice` Whibh *1szth, subje'ct of this it is 'nezessary that .tho release of th r'lay's 14and 2:2136' contrpllodin 'rel-ation ltothe olosurond breaking oftho mainnxili'ary circuit by the; brush 3Q and com iiuct'ing segment 2Q so thatthe oiilytsparking' 85 takes 4plagne on the cornmuttor. A

- 'For this purpose tliergi.V are auxiliary 'Controlling circuits for"th rlays 14' and 2Q which are respocti veljy' l aseociadf with switcheswhich are 'definitely spac'od inrela 40 tion to the rotating"couunutatbr in fthe`ma`in A14 includ tfhepatryjyr, thegbrush 35, -ripg'mentiL .rlfind gome-v distanco beyond svgincm-zS-l, thus giymglth mai-nauxiliary cirfuif spacv Polity if., 19.

As ong as relay arm 13 'is lpwmrelay magnet 22" is anergizil throughthewrcuit 'including batteryl 17.Y ands1iicr i terminals 24. Now whenrelay alim '1 3 relaziona-asi het@ inbefrerfdleiacred, it is necosarythat taarryinirls 1.9 remain closed until muniti-1113s om of contactwith segment L69 ufl thx;L "11min uuxillihry: ogii'cuit,4 that is, umiltin'A mitin uxiliai'y'cirj-it is broken. '.l `ln\n tln anxl iurycit-cuit or polity .umgnet JZ-is-b-ro'kon hy brush` missin oui:v .ofconti-nrt withnxvg l.'l Wil heutigen that'seguito-11;4l isenough t0 boomrq'oteiy broken bofmft' arm 21 rises and opens the. terniimtl As therotation of the switching -omnisin tors is at the nate of about 30 porsommi., tin1 sequence of operations is wry rapid nml ies. fai' as'tlieoprator handling the kry 1%.. concerned? he controlling tlm .siggzxnlf-:in. usual,

The spaced terminals 211, 39 nml, 19 an;

arranged lastshown in relation With'the ,relay arms '13. and'f21 thatthe cicuit in which .thesespced tc'rminalszare includml can only bactivo 'when th .ralaylarnis are; down, othrw'i'se tho'rotn'tion of theoommutators ln-'oulcl intermittently energiz, the rlays.. As

Shown lin:` the figures, ,the repective pmrnu- If contacts afterthel'rolay arms 13 and 21, lliave initially boon' brought ,lown by thefio'ratin Of .key-1 G. ,As hert-,inleforiystarted, thefhand key cntn'ol:the duration' ofolosuro'ofthe mitin Circuit except for that shortperiod, of.

Thu it `is`necessary to' prvent the denr'# gizing of relay 14 until themain auxiliary terminali@ permits: th;

circuit is complete. For this pu ose an auxiliary energizing circuit issupp iedl for relay magnet 14. This circuit includes a rotatingcommutator with A) 'whose conducting segment 33 is oppositely disposedin relation to the main conducting segment 29 andl occupies an equalangular distance with the exception that commutator segment B slightlyoverlaps the insulating part of commutator C. If the key 16 is raisedatan instant of time when` the main auxiliary circuit' is open onaccount of brush 30 being on insulating segment 31, the contact 11 willremain closed since ,the auxiliary circuit for relay 14 is completethrough circuit 17, 15, 32, '35, 33,.

And .relay 14 will remain energized until brush 35 slips olf segment 33when relay 14 will bedenergized. Terminals 11 can then open'4 Withoutspark.

When .relay 14 is denergizcd and relay arm 13 rises, thus breakingterminals 24 Vand breaking thc circuit through 17, 23, 24, 23, 23, 17 inwhich is included the relay 22, it is necessary to provide an auxiliaryenergizingr circuit for relay 22, which will keep relay 22 acti-ve, thusmaintaining the closui'e of terminals 19 until themain auxiliary circuithas been broken by brush '30 slipping oil?` commutator segment 29. -Thenterminals 19 can be opened Without spark. For this purpose l-an auxiliaenergizing circuit for relay 22 issupplie i conducting segment 41 isdefinitely spaced inrelation to main commutator segment and extends4some distance beyond it se that when brush 30 is on segment29, brush 43is on segment 41 and remains on 41 until` brush 30 passes completely offsegment 29.

When relay 14 is denergized by brush, oli 33, and terminals 24 are 35slippin opened, re ay 22 will be energized through the circuit 17, ;23,39, 38, 44, 45, 41, 43, ves, 23, ,17 and will remain energized untilbrush 43 isy out of contact with' segment 41. Thereuponrelay arm 21 willrise breaking terminals 39 `and preventingthe relay `22 from again beingenergized by theI rotation of the commutator C until it hasagain beenbrought down by. theoperationof. relay 14. Likewise when termina s 24are broken, the

successive closing of switch-B willl not cause' a renergizationof relay14. If this precaution were not taken, signals would be sent outintermittently by the rotation vof the switches.

However, the associated switches can only energize their respectiverelays .during one engagement Aof their conducting segments with thebrushes following,r the 4releasement of the telegraphic key 16. n

This. period of time can be so shortened B (non the saine shaft l Thiscircuit in-x cludes a rotating'commutawr C on the same.

' shaft with the main commutator' A. The- --,Having thus described my byspeeding up the rotation of the commutators that the momentaryprolonging of the closure of the maincircuit 10 will have anegligibleeffect on the signadngthe protha'n the period While itislongation .bein'g'far shorter of time represented by a dot.

stated that the speed of the associated com in iitators` is 30revolutions per second, it will be understood vthat-this certain speedis not essentialfto the ell'cient operation of the device. 7

Bycausing the arcing'or sparking to' occur on the heavy commutator'segment the contacts for controlling the main sending 'circuit aresaved' and the danger of fusing is overcome. 1

The end of the in ainA conducting segment A Will be worn and burnt inAtime and l prcfer to make them removable so that they may be replaced asoccasion requires.

ln Fig. 2'tlie the same throughout, with the exccp'timi that the secondrelay has its initia' ener gizingr circuit 23 controlled directly by keyy16,/and additional contact 16 being provided for the purpose. l

AWhile I have slio'ivn. and described licrcin two specific forms of myinvention, it will be understood, nevertheless, that the saine issusceptible of other modifications and l and ar- 9' that many changes inconstruction rangement of the several parts inay be eniployed withoutdepartin r from my ifnvention as disclosed in the appended claims.

invention, whatI claim and desire to secure by lLetters Patent iS- 1. Ina telcgraphicsending circuit, a main circuit provided with spacedterminals by the opening and closing of which the .main

circuit isvdirectly opened and closed and-'105 signals are despatched,an aux-i iary circuit" lshunted around said terminals, said auiil larycircuit including an automatic switch in series with spaced terminals bing of which said automatic switch tive t make and hreaksaid auxiliarycire-f cuit. .2. In a telegraphic sending circuit, ania'in,vv circuityprovided with direct despatch of signals in combination with anauxiliary circuit. shunted'around' said main circuit, terminals, saidauiriliary circuit including in series connection a rotat ing switch and4spaced terminals by the clos 12,5y

nals whereby said main'crcuit is directly y closed for signalingpurposes,an associated ,arrangement is substanti-aily spacedterminals??- adapted to be opened and closed forv the terminals, op- 'isi' included in said auxiliary circuit forbreak- 'ing .r9 a E1 In atelegraphlc sending circuit hav- ,r s aced terminals a relay a key-con-?ue the same at a point removedL from the -controlled contacts.

local circuit for operating the relay; a contact operated by the relayfor closing the mainsending circuit, an auxiliary circuit yin shunt withthe main sending circuit, a

second relay, a contact operated by the secnd. relay forclosing theauxiliary circuit, ar

primary energizing circuit for the second Yrelay closed by a contactoperated by the first relay when the latter isenergized, a secondlcircuit for breaking the same prior to the breaking ,of the `auxiliarycircuit by its switch.

12. Ina telegraphic sending circuit hav ing spaced terminals, a relay, akey-coni trolled local circuit for operating' the relay,

a contact operated by the relay for closing the main sending circuit, anauxiliarycir cuit in shunt with the main sending circuit, a secondrelay, a Contact operatedby the fseeond relay for closingthe auxiliarycircuit, la primary energizing circuit for the second relay closefl by acontact operated by the first relay when the latter' is energized, ahintermittent 'switch included in said auxiliary circuit, a secondaryenergizing circuit for the second relay closed by the closure of thcauxiliary circuit, whereby the auxiliary ciri cuit wilremain closedindependently of the the auxiliary circuit,. ,said

switches each including rotatable conduct-A 50 ing and insulatingsegments and stationary i release of the first mentionedrelay-operated2V contact and will be broken by 'said switch,

land an intermittent switch included in said 'secondary energlzmgcircuit and operable t6 break said circuit following the breaking ofintermittent i brushes so arranged that when a brush of the first switchis on a conducting segment a brush ofthe second switch is also on aconond relay, 1e

vergizin'g circuit for the second rela ductin segment, the latter beingextended beyon the conducting segment of the first switch. 4

13. In a'telegraphic sending circuit havin spaced terminals, a relay, akey-controlla primary circuit for operating said relay, a contactoperatedby the relay for closing the main sending circuit, an auxiliarycircuit in shunt with the inain sending circuit, a seca contact operatedthereby for auxiliary circuit, a primary enl closed by a contactoperated by the ,first re ay, secondary energizing circuits for each o fsaid relays closed by contacts operatedby the res ective relays, 4anintermittent switch inc uded in said auxiliary circuit and in each ofthe secondary relay circuits, whereby the auxiliary circuit will remainclosed 1ndc closing t pendently of the release of the first mentionedrelay-operated contact andl will be broken by its switch, saidintermittent switches each including rotatable 'conducting andinsulating segments and stationary brushes so arranged that when vabrush of the switch in the auxiliary circuit is on a conducting segment,a brush of the switch in the circuit of the second relay is also on aq,conducting segment, the latter being extended beyond the conductingsegment of the i first switch and the switch in the circuit of -thefirst relay having its conducting segment saidjajuxiliarycircult on thcrelease of said key-controlled fmeans.

n'testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses. t l

EDWIN s. PRIDHAM.

Witnesses: I

J oHN H. Humaine, W. W. Hmm.

